Two-photon absorption enhancement using photonic jets

We point out theoretically and experimentally the possibility to enhance a non-linear effect by using photonic jets. The new possibility to highly concentrate visible light with micrometric dielectric spheres is illustrated simulating the situation in water. The photonic jet is a highly energetic beam with special properties that deviate from geometrical optics. Its ability to enhance non-linear effects is experimentally demonstrated by studying the two-photon excited fluorescence of rhodamine B.